Added missing include to adj_jac_apply tests (tnx cpplint) (Issue #963)
Added missing include to adj_jac_apply tests (tnx cpplint) (Issue #963)

stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math